Humic acid rejection and flux decline with negatively charged membranes of different spacer arm lengths and charge groups

2013 ◽  
Vol 435 ◽  
pp. 38-45 ◽  
Author(s):  
Jiahui Shao ◽  
Ling Zhao ◽  
Xiuwen Chen ◽  
Yiliang He
Keyword(s):  
Humic Acid ◽  
Flux Decline ◽  
Spacer Arm ◽  
Charged Membranes

scholarly journals IMMOBILIZATION OF HUMIC ACID ONTO CHITOSAN USING TOSYLATION METHOD WITH 1,4-BUTANEDIOL AS A SPACER ARM

2012 ◽  
Vol 12 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Uripto Trisno Santoso ◽  
Radna Nurmasari ◽  
Dewi Umaningrum ◽  
Sri Juari Santosa ◽  
Bambang Rusdiarso ◽  
...  
Keyword(s):  
Humic Acid ◽  
Phthalic Anhydride ◽  
Spectrophotometric Method ◽  
Tosyl Chloride ◽  
Spacer Arm

Immobilization of humic acid (HA) onto chitosan using tosylation method with 1,4-butanediol as a spacer arm has been evaluated. Chitosan was phthaloylated selectively using phthalic anhydride in dimethylformamide as solvent with addition of 5% water (v/v) as cosolvent prior to be tosylated. N-phthaloyl-chitosan and HA were tosylated using tosyl chloride in excess and triethylamine as catalyst at temperature < 10 °C for 12 h. The 6-O-tosyl-N-phthaloyl-chitosan was reacted with 1,4-butanediol in order to obtain a spacer arm attached chitosan. The 6-O-butanol-N-phthaloyl-chitosan was activated by reacting with tosyl chloride. For evaluation on immobilization of HA on chitosan with and without spacer arm, 6-O-tosylbutane-N-phthaloyl-chitosan was reacted with HA and the 6-O-tosyl-N-phthaloyl-chitosan was reacted with HA. The HA immobilized onto chitosan was characterized by XRD and FTIR spectrophotometric method. The result showed that HA can be immobilized covalently onto chitosan after attaching 1,4-butanediol as spacer arm onto 6-O-tosyl-N-phthaloyl-chitosan and activating the product with tosyl chloride, but HA cannot be reacted directly onto 6-O-tosyl-N-phthaloyl-chitosan.

Effects of clay on the fouling by organic substances in potable water treatment by ultrafiltration

1994 ◽  
Vol 30 (9) ◽  
pp. 159-168 ◽  
Author(s):  
C. H. Kim ◽  
M. Hosomi ◽  
A. Murakami ◽  
M. Okada
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Water Treatment ◽  
Fulvic Acid ◽  
Potable Water ◽  
Cross Flow ◽  
Clay Material ◽  
Flux Decline ◽  
Clay Materials ◽  
Potable Water Treatment

In water treatment by ultrafiltration, effects of clay on the fouling due to organic matter in cross-flow ultrafiltration were evaluated by fouling model materials and clay. Fouling model materials selected were BSA (Bovine serum albumin, MW68,000), Dextran (MW70,000), and humic acid (MW8,000-200,000) at a size larger than molecular weight cut-off (MWCO 50,000, polysulfone) and alpha-lactalbumin, Dextran (MW9,300), fulvic acid (MW8,000) for smaller size than and that kaolin was selected as a clay material. The flux of BSA, Dextran (MW70,000) increased with an increase in the amount of kaolin, and the flux of alphalactalbumin, Dextran (MW9,300), fulvic acid did not increase with kaolin. In contrast, the flux of humic acid decreased with an increase in the quantity of kaolin. It was found that in the direct ultrafiltration of river water clay materials did not affect the flux decline, and could contribute to the prevention of fouling due to organic matter. It seemed that the pore size of membrane plays an important role in the effect of clay on the fouling due to organic matter.

Stability of charged membranes

1990 ◽  
Vol 51 (8) ◽  
pp. 689-695 ◽  
Author(s):  
D. Bensimon ◽  
F. David ◽  
S. Leibler ◽  
A. Pumir
Keyword(s):  
Charged Membranes

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

Changes in the Humic Acid–Metal Complexation Characteristics Depending on Humification Degree / Humīnskābju – Metālu Kompleksveidošanās Rakstura Izmaiņas Atkarībā No Humifikācijas Pakāpes

2012 ◽  
Vol 51 (3) ◽  
pp. 228-237
Author(s):  
D. Dudare ◽  
M. Klavins
Keyword(s):  
Humic Acid ◽  
Stability Constants ◽  
Humic Acids ◽  
Complex Stability ◽  
Peat Layer ◽  
Raised Bog ◽  
Complexing Capacity ◽  
Humification Degree ◽  
Complexation Process ◽  
Complex Stability Constants

The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids isolated from two well-characterized raised bog peat profiles in respect to the basic properties and humification characteristics of the studied peats and their humic acids. The complex stability constants significantly change within the studied bog profiles and are well correlated with the age and decomposition degree of the peat layer from which the humic acids have been isolated. Among factors that influence this complexation process, molecular mass and ability to form micellar structures (supramolecules) of humic substances are of key importance.

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